diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 5b0aebac0f0..dd961d289e2 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -9489,7 +9489,7 @@ abstract class CommonObject
 	 * @param 	User 	$user       			User that deletes
 	 * @param 	bool 	$notrigger  			false=launch triggers after, true=disable triggers
 	 * @param	int		$forcechilddeletion		0=no, 1=Force deletion of children
-	 * @return 	int             				<=0 if KO, 0=Nothing done because object has child, >0 if OK
+	 * @return 	int             				<0 if KO, 0=Nothing done because object has child, >0 if OK
 	 */
 	public function deleteCommon(User $user, $notrigger = false, $forcechilddeletion = 0)
 	{
diff --git a/htdocs/modulebuilder/template/class/api_mymodule.class.php b/htdocs/modulebuilder/template/class/api_mymodule.class.php
index 736fd9ddc38..ce92ef5ea8e 100644
--- a/htdocs/modulebuilder/template/class/api_mymodule.class.php
+++ b/htdocs/modulebuilder/template/class/api_mymodule.class.php
@@ -293,7 +293,9 @@ class MyModuleApi extends DolibarrApi
 			throw new RestException(401, 'Access to instance id='.$this->myobject->id.' of object not allowed for login '.DolibarrApiAccess::$user->login);
 		}
 
-		if (!$this->myobject->delete(DolibarrApiAccess::$user)) {
+		if ($this->myobject->delete(DolibarrApiAccess::$user) == 0) {
+			throw new RestException(409, 'Error when deleting MyObject : '.$this->myobject->error);
+		} elseif ($this->myobject->delete(DolibarrApiAccess::$user) < 0) {
 			throw new RestException(500, 'Error when deleting MyObject : '.$this->myobject->error);
 		}